Garmin 800 Wheelsize Question

Secteur

Hi,

I added a new bike profile to my Garmin 800, and on the first ride it automatically calculated the "wheel size" as 2115mm.

I can manually adjust this if required.

I use a Fulcrum Racing 3 with 25mm GP4000S tyres.

Does anyone know how I can manually check what the wheel size is, to ensure my Garmin is calculating distance correctly?

My other bike runs Aksium Elites with GP4Seasons, and the Garmin automatically calculated the wheel size on that as 2108mm.

I assume the automatic calculation depends on where along the spoke I place the magnet - perhaps if it is nearer the rim / hub it would give a different calculation?

Any advice gladly welcome, and thanks!

JackPozzi

Automatic calculation simply uses the GPS to work out when you've covered a set distance (about a km I think) then uses the number of wheel revolutions to work out wheel size, so where the magnet is makes no difference assuming it is located in a position where it registers correctly. Simplest way to measure your wheel size is put a chalk mark on the tyre, sit on the bike and roll forward a bit hopefully leaving some chalk on the floor then measure the distance between marks

Secteur

JackPozzi wrote:

Automatic calculation simply uses the GPS to work out when you've covered a set distance (about a km I think) then uses the number of wheel revolutions to work out wheel size, so where the magnet is makes no difference assuming it is located in a position where it registers correctly. Simplest way to measure your wheel size is put a chalk mark on the tyre, sit on the bike and roll forward a bit hopefully leaving some chalk on the floor then measure the distance between marks

Great, thanks for that!